The invention relates to an apparatus for insufflating a body cavity with an insufflation gas, comprising an insufflation device having a delivery line for delivering the insufflation gas to the body cavity. The invention further relates to a method for insufflating a body cavity with an insufflation gas, said method comprising the following step: provision, by an insufflation device, of an insufflation gas for delivery to a body cavity.
Such an insufflation apparatus and such a method are known, for example, from the article entitled “Die Laparoskopie in der Gynätkologie” by K. Semm in “Geburtshilfe und Frauenheilkunde”, volume 11, November 1967. With the aid of the insufflation device, the so-called insufflator, an insufflation gas, usually carbon dioxide gas (CO2 gas), is introduced into a body cavity of a human or animal, for example into the abdominal cavity. The insufflation gas inflates the abdominal cavity so as to create the viewing and operating space which is needed between the internal organs and the abdominal wall in order to permit examination or surgery with the aid of an endoscope.
In addition to the insufflation gas, it is also possible that other gases will collect in the abdomen, for example nitrous oxide (N2O) and/or methane (MH4), which can result in explosive gas mixtures within the abdomen. Gas explosions may therefore occur, especially in connection with electrosurgical procedures.
Nitrous oxide is used for anaesthesia. It can diffuse from the bloodstream into the intra-abdominal cavity. If a nitrous oxide concentration of ca. 29% is exceeded, there is an increased risk of explosion of the gas mixture located in the abdominal area. The diffusion behavior of nitrous oxide in the abdominal area of pigs is known from the article “Nitrous Oxide Fraction in the Carbon Dioxide Pneumoperitoneum During Laparoscopy Under General Inhalation Anaesthesia in Pigs” by P. Diemunsch, Klaus D. Torp, T. Van Dorsselaer, D. Mutter, A. M. Diemunsch, R. Schaeffer, G. Teller and A. Van Dorsselaer. The article describes how, with the aid of a catheter and a gastight syringe, samples were taken from the abdominal cavities of pigs at ten-minute intervals. Nitrous oxide was used for anaesthesia. The abdominal cavities were inflated with carbon dioxide gas. The behavior of the nitrous oxide concentration in the abdomen was observed over a particularly long observation period. After approximately two hours, the critical limit of 29% nitrous oxide concentration is reached. After about nine hours, the nitrous oxide concentration rises to a value of just over ca. 66%.
The measuring method described in the article involving a catheter and a gastight syringe may well be acceptable for a scientific test. However, such an approach is not suitable for a typical endoscopic procedure in which the patient must be treated with great care and in which the operating physician must focus his concentration entirely on the patient.
A further problem in intra-abdominal interventions is that the patient's intestine may inadvertently be damaged or perforated. This danger is particularly great when using electrosurgery instruments. Damage to the intestine results in the escape of intestinal gases which contain methane. The methane can cause explosions. However, a far greater problem is that of the damage to the intestine not being detected during the intervention. In the postoperative period, this can lead to serious complications, or even to the death of the patient. However, an analysis of the gases in the abdominal area in the manner known from the abovementioned article is on account of the complicated collection of samples not really practicable with respect to methane.
It is therefore an object of the invention to permit early and reliable detection of any complications which may occur during an intervention in which an insufflation gas is insufflated into a body cavity, in particular into the abdominal cavity, of a human or animal.